The invention relates to an expanded metal mesh and to a tool for producing same.
Known is an expanded metal mesh comprising an e.g. rhombic or square mesh in the furnished condition, the geometry of which automatically couples expansion lengthwise and contraction crosswise. This known reaction results in such an expanded metal mesh still being difficult to shape to conform to surface areas having pronounced three-dimensional curvature even when the material is itemized, folded or nicked and doubled.
An expanded metal mesh for plastic modelling as a reinforcement inlay for a covering material in the form of curves, webs or strips featuring high conformity to complex three-dimensionally shapes for use e.g. as verge and edge weatherstripping is known from DE 36 42 063. This covering material consists substantially of an elastomeric layer and the expanded metal mesh serving as a reinforcing element. This expanded metal mesh features an expansion of 50 to 150% lengthwise and xe2x89xa620% crosswise, each mutually excluding the other, as well as a return xe2x89xa65%.
Known from EP 0 797 486 is an expanded metal mesh permitting very good plastic modelling. In this known expanded metal mesh, two nodes staggered from row to row in the mesh are parted by a nick perpendicular to the actual expanded cut. One such expanded metal mesh excels by being excellently conducive to three-dimensional shaping.
Known in conclusion from DE 198 21 574.6 is a means of improving the expansion response of the expanded metal mesh by creating an additional transverse corrugation in the sheet metal by either using trapzoidal or corrugated sheet as the starting material or by producing the transverse corrugation in a flat expanded metal mesh in the course of fabrication, subsequent flat rolling then creating links in the mesh which are bent S-shaped.
The drawback in all of these known expanded metal meshes is that they do not permit cost-effective manufacture, they also being more difficult to handle than normal expanded metal mesh.
The invention is thus based on the objective of providing an expanded metal mesh for cost-effective manufacture whilst permitting expansion in two directions or at least no crosswise contraction in the presence of lengthwise expansion. A further objective of the invention is to provide a tool for cost-effective manufacture of expanded metal mesh.
The expanded metal mesh in accordance with the invention is characterized by it being cut, for example, so that certain links remain joined merely ultrathin, resulting in some of the nodes in the mesh being configured as designed break points. Now, manufacture is the same as for normal expanded metal mesh and the resulting expanded metal mesh can be handled and worked just as easily as normal expanded metal mesh. More particularly, the expanded metal mesh in accordance with the invention has a uniform smooth surface with no risk of snagging, as is the case, for example, with an expanded metal mesh in accordance with EP 0 797 486 in which nodes in the mesh are parted by a nick perpendicular to the actual expanded cut.
The mesh in accordance with the invention can be filled out or coated with curing or elastomeric polymerizing or dry substances or compounds and thus are useful e.g. as lathing as well as in roofing applications as products having become popular as xe2x80x9clead replacementsxe2x80x9d. Further possible applications include:
1. spacers for cavity claddings,
2. tailored packings for spherical objects and the like,
3. drying grids and filter cages for industrial and domestic purposes,
4. mattings as employed in automotive repair as a replacement for glass-fiber plastics.
Further applications are conceivable in which forces need to be absorbed in an overload situation such as e.g. in guards on rotating machines or highway safety fencing.
It is good practice to configure the nodes in the mesh in accordance with the invention as a regular sequence of designed break points, by, for example, making every second or two from three nodes a designed break point staggered from row to row in the mesh.
Another variant consists of configuring the mesh, at least in localized portions thereof, throughout with designed break points, whereby marginal zones may be configured without designed break points to prevent unwanted tearing. To increase the stability and strength such meshes may be connected to each other at an angle and more particularly at right angles and at the junctions.
The mesh in accordance with the invention including some nodes configured as designed break points is also combinable with an expanded metal having an improved expansion response in accordance with DE 198 21 574.6. Starting with trapezoidal, corrugated or similar shaped sheet metal the nicks are incorporated in the mesh so that selected links remain connected to each other only by ultrathin locations to thus form the designed break points. The junctions at these modes configured in the mesh as designed break points are, however, sufficiently rugged to break only when shaping as specified is done.
The weakened designed break nodes in the mesh may be produced with a conventional tool by setting a deeper cutting depth already during manufacture, although such a conventional tool may be used, however, to produce only designed break nodes throughout in the complete mesh.
Should, however, designed break points be required only in a regular sequence, for example only at every second or third node, this can be done with a tool having differingly deep gullets, such a tool producing in a xe2x80x9cnormalxe2x80x9d cutting depth simultaneously conventional nodes and designed break nodes at the locations with less deep gullets. Instead of designed break nodes, a smooth parting of some nodes may result with less deep gullets in obtaining a mesh as set forth in EP 0 797 486, i.e. a mesh in which every second and/or third node is parted staggered from row to row of the mesh, resulting in a mesh which can be excellently formed spherical.